Screening arrangement

ABSTRACT

The screening arrangement, in particular a Venetian blind, is intended for installation in a roof window and comprises a screening length having a number of mutually connected elements as well as profile lists to be mounted on each of the side members of the sash and each having a track for receiving a structure displaceable along the track, the structure comprising a spring housing and a slide shoe. The slide shoe is provided with an abutment surface for the elements of the screening length during their gathering during raising of the screening arrangement. A bottom list of the screening length facing the bottom member of the frame is connected at each end with the displaceable structure and loaded in the direction of the bottom member of the sash by a coil spring rotatably mounted in the spring housing, the uncoiled portion of the spring extending in the track in question from the displaceable structure to a fixing point at the bottom member of the sash. The abutment surface of the slide shoe extends in the longitudinal direction of the track to such an extent that it may receive a predetermined number of screening elements, and the spring housing and the slide shoe are displaceable relative to each other in view to reducing the extension of the abutment surface. The spring housing may for instance be guided in a track in the slide shoe.

BACKGROUND OF THE INVENTION

The present invention relates to a screening arrangement, in particulara Venetian blind, for installation in a roof window with a sashcomprising a top member, a bottom member and two side members, whichscreening arrangement comprises a screening length having a number ofmutually connected elements as well as profile lists to be mounted oneach of the side members of the sash and each having a track forreceiving a means displaceable along the track, said means comprising aspring housing and a slide shoe with an abutment surface for saidelements of the screening length during their gathering through raisingof the screening arrangement, in which a bottom list of the screeninglength facing the bottom member of the sash at each end is connectedwith the displaceable means and loaded in the direction of the bottompiece of the sash by a coil spring rotatably mounted in the springhousing, the uncoiled portion of which extending in the track inquestion from the displaceable means to a fixing point at the bottommember of the sash.

A screening arrangement of this type is known from DK publishedspecification No. 160 627. Such screening arrangements are used inwindows of many different sizes and thus have a differing number ofscreening elements. It is therefore necessary to produce the slide shoesof the displaceable means with different lengths depending on the lengthof the screening arrangement. This entails in addition to the drawbacksof a purely technical nature in connection with the manufacture also ahigher price of the screening arrangement as a whole.

SUMMARY OF THE INVENTION

It is the object of the present invention to improve a screeningarrangement of the type mentioned by way of introduction such that oneand the same displaceable means may be used in screening arrangements ofany length.

This object is met by means of a screening arrangement which ischaracterized in that the abutment surface of the slide shoe extends inthe longitudinal direction of the track to such an extent that it mayreceive a predetermined number of screening elements, and that thespring housing and the slide shoe are displaceable relative to eachother in view of reducing the extension of the abutment surface.

In this way, the displaceable means may be manufactured as astandardized unit, in which the slide shoe has an abutment surface whichis so dimensioned that it may receive all screening elements of evenvery long screening arrangements. By letting the spring housing bedisplaceable relative to the slide shoe it now becomes possible to bringthe upper elements of shorter screening arrangements, which would nototherwise be raised, into abutment against already raised elements, thespring housing and the bottom list continuing their movement in thedirection towards the top member of the sash, even though the slide shoehas reached its end position.

The displaceable connection between the spring housing and the slideshoe is in an embodiment, which from a constructional point of view isvery simple, established by the spring housing being guided in a rack inthe slide shoe.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in detail in the following by means ofan example of an embodiment and with reference to the schematic drawing,in which

FIG. 1 shows a roof window with a screening arrangement according to theinvention, including an enlarged cross-section of a side member of theroof window,

FIG. 2 a perspective view of a detail of the screening arrangementaccording to the invention,

FIGS. 3 and 4 lateral views, partially sectional, of the screeningarrangement according to the invention, the screening elements beingraised partially and completely, respectively, and

FIG. 5 a sectional view along the line V--V in FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a roof window 1 with a frame 2 and a sash hingedlyconnected therewith, said sash comprising a top member 3, a bottommember 4 and two side members 5 carrying a window pane 6. At the insideof the pane 6 a screening arrangement 7 is installed, which in theembodiment shown is a Venetian blind, but which also for instance mightbe an exterior roller shutter or a folding blind. The Venetian blind 7is provided with screening elements 8 in the form of slats and ends inthe lower end, i.e. the end facing the bottom member 4 of the sash, in abottom list 9. The bottom list 9 is guided in a way not shown in detailin FIG. 1 profile lists 10 mounted on the side members 5 of the sash theside members likewise guiding the slats 8 through recesses 8a in theslats. The positioning of the profile lists 10 also appear from thedetailed cross-sectional portion of FIG. 1. The Venetian blind 7 isoperated, i.e. the raising and lowering thereof as well as adjustment ofthe inclination of the slats, by means of a cord 11 which is guided to adriving device, not shown in detail, which is placed in a top box 12fastened to the top member 3 of the sash, said box accommodating amongothers the cords of the Venetian blind. Operation may also be carriedout by means of an electric driving device of a type known per se.

As shown in FIG. 2 each profile list 10 has a track 13 with an openingwhich in the mounted position of the screening arrangement faces thewindow pane 6. The profile list 10 is in view of being fastened to theside member 5 of the sash provided with a flange 14. In FIG. 2 theprofile list 10 is intended for being mounted on the sash side member,which in FIG. 1 is the left one, and the profile list for the oppositeside member is relative thereto mounted reversely.

A slidable means comprising a spring housing 15 and a slide shoe 16 isplaced in connection with the track 13. The displaceable connectionbetween the slide shoe 16 and the track 13 is established thereby thatthe slide shoe at its bottom side, i.e. the side facing the track 13, asshown in FIGS. 3 and 4, is provided with projections 21a and 21b, whichseen in the cross-sectional direction of the track have the form of areversed T in engagement with the track 13, which appears most clearlyfrom FIG. 5. The bottom list 9 of the Venetian blind is at each endseated in the spring housing 15, which in turn by means of a track 17 inthe slide shoe 16 is displaceably guided therein. The spring housing 15is in the same manner as the slide shoe 16 provided with projections 22aand 22b at its bottom side, said projections being guided through thetrack 17 in the slide shoe 16 and the track 13 of the profile list 10.

The spring housing 15 accommodates a rotatably mounted coil spring, thecoiled portion of which is positioned in the spring housing itself, andthe uncoiled portion 18 of which, shown in FIGS. 3 and 4, extends in thetrack 13 of the profile list 10 down to a fastening point 19 at thelower end of the profile list 10. In this way the spring housing 15 andconsequently the slide shoe 16 and the bottom list 9 of the Venetianblind get in the mounted position spring-loaded in the direction towardsthe bottom member of the sash. Without this spring-loading it would notbe possible to lower the Venetian blind completely in respect of windowswhich are mounted in roofs having a slight inclination.

The functioning of the displaceable means appears from FIGS. 3 and 4. InFIG. 3 the Venetian blind is partially raised, and the lower slats aregathered and abut an abutment surface 20 on the slide shoe 16. Onaccount of the friction between the spring housing and the slide shoeand/or as shown a shoulder portion 23 on the slide shoe 16, the springhousing 15 remains in the lower part of the track 17 in the slide shoe16. Therefore, the spring housing 15 and the slide shoe 16 move upwardstogether in the track 13 of the profile list 10. The raising continuesin this manner, the slats being gathered until the upper end of theslide shoe 16 touches the top box 12. The slide shoe 16 is now in itsupper end position, and gathering of the last, i.e. the upper slats,takes place thereby that the spring housing 15 is displaced in thedirection towards the top box 12 in the track 17 in the slide shoe 16,until all slats abut each other.

We claim:
 1. The combination of a roof window (1) having a sash comprising a top member (3), a bottom member (4) and two side members (5); and a screening arrangement installed in the roof window, wherein the screening arrangement comprises:a screening length having a number of mutually connected elements and a bottom list; profile lists (10) to be mounted on each of the side members of the sash, each profile list having a track (13) and an end adapted to be positioned adjacent to the bottom member of the sash, said track having a longitudinal direction adapted to extend along one of the side members of the sash; a structure received by and displaceable along the track, said structure comprising a spring housing (15), a coil spring rotatably mounted in the spring housing, a slide shoe (16) having an abutment surface (20) for abutting said elements (8) of the screening length during their gathering through raising of the screening arrangement, and a mounting structure mounting said spring housing on said slide shoe for movement relative to said slide shoe in the longitudinal direction of said track, the bottom list (9) of the screening length being connected at each end with a respective one of the displaceable structures and being loaded in the direction of said end of said profile list by the coil spring, the coil spring having an uncoiled portion (18) extending in the track (13) from the displaceable structure to a fixing point at said end of said profile list, the abutment surface (20) of the slide shoe (16) extending in the longitudinal direction of the track (13) sufficiently to receive a predetermined number of screening elements (8), wherein said mounting structure comprises a track in the slide shoe, the sprint housing being guided in said track in the slide shoe.
 2. The combination according to claim 1, characterized by means for holding the spring housing (15) stationary at an end of the slide shoe (16) facing said end of said profile list during the raising of the screening arrangement.
 3. The combination according to claim 2, characterized in that said means for holding comprises a shoulder portion (23) on the slide shoe (16).
 4. The combination according to claim 1, wherein said mounting structure is a mounting structure slidably mounting said spring housing on said slide shoe for sliding movement relative to said slide shoe, providing an additional displacement of said spring housing relative to said track.
 5. The combination according to claim 1, wherein said mounting structure comprises a mounting structure mounting said spring housing on said slide shoe for movement of the entire spring housing relative to the slide shoe.
 6. The combination of a roof window (1) having a sash comprising a top member (3), a bottom member (4) and two side members (5); and a screening arrangement installed in the roof window, wherein the screening arrangement comprises:a screening length having a number of mutually connected elements and a bottom list; profile lists (10) mounted on each of the side members of the sash, each of said profile lists having a track (13) and an end positioned adjacent to the bottom member of the sash, each of said tracks having a longitudinal direction extending along one of the side members of the sash; two slidable structures received by and displaceable along the tracks, each of said slidable structures comprising a spring housing (15), a coil spring rotatably mounted in the spring housing, a slide shoe (16) having an abutment surface (20) for abutting said elements (8) of the screening length during their gathering through raising of the screening arrangement, and track means for slidably mounting said spring housing on said slide shoe for movement relative to said slide shoe in the longitudinal direction of said tracks, wherein the bottom list (9) of the screening length is connected at each end with a respective one of the slidable structures and is loaded in the direction of said end of said lists by the coil springs, the coil springs having an uncoiled portion (18) extending in the tracks (13) from the slidable structures to a fixing point at said end of said profile lists, the abutment surface (20) of the slide shoes (16) extending in the longitudinal direction of the tracks (13) sufficiently to receive a predetermined number of screening elements (8).
 7. The combination according to claim 6, wherein said means for mounting comprises means for slidably mounting said spring housing on said slide shoe for sliding movement relative to said slide shoe and for providing an additional displacement of said spring housing relative to said track.
 8. The combination according to claim 6, wherein said means for mounting comprises means for mounting said spring housing on said slide shoe for movement of the entire spring housing relative to said slide shoe. 